21754331 has 4 divisors (see below), whose sum is σ = 21816312. Its totient is φ = 21692352.

The previous prime is 21754307. The next prime is 21754351. The reversal of 21754331 is 13345712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21754331 is a prime.

It is a super-2 number, since 2×21754331² = 946501834515122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21754331.

It is not an unprimeable number, because it can be changed into a prime (21754351) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30461 + ... + 31166.

It is an arithmetic number, because the mean of its divisors is an integer number (5454078).

Almost surely, 2^21754331 is an apocalyptic number.

21754331 is a deficient number, since it is larger than the sum of its proper divisors (61981).

21754331 is an equidigital number, since it uses as much as digits as its factorization.

21754331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61980.

The product of its digits is 2520, while the sum is 26.

The square root of 21754331 is about 4664.1538353704. The cubic root of 21754331 is about 279.1570353054.

The spelling of 21754331 in words is "twenty-one million, seven hundred fifty-four thousand, three hundred thirty-one".